The field of the invention relates generally to methods of preparing the Bruton's Tyrosine Kinase (“BTK”) inhibitor compound 2-{3′-hydroxymethyl-1-methyl-5-[5-((S)-2-methyl-4-oxetan-3-yl-piperazin-1-yl)-pyridin-2-ylamino]-6-oxo-1,6-dihydro-[3,4′]bipyridinyl-2′-yl}-7,7-dimethyl-3,4,7,8-tetrahydro-2H,6H-cyclopenta[4,5]pyrrolo[1,2-a]pyrazin-1-one. The field of the invention further relates generally to methods of preparing tricyclic lactam compounds.
The BTK inhibitor compound 2-{3′-hydroxymethyl-1-methyl-5-[5-((S)-2-methyl-4-oxetan-3-yl-piperazin-1-yl)-pyridin-2-ylamino]-6-oxo-1,6-dihydro-[3,4′]bipyridinyl-2′-yl}-7,7-dimethyl-3,4,7,8-tetrahydro-2H,6H-cyclopenta[4,5]pyrrolo[1,2-a]pyrazin-1-one of the following structure:
is known from U.S. publication US 2013/0116235 A1 as a BTK inhibitor that is useful for the treatment of a disease or disorder selected from immune disorders, cancer, cardiovascular disease, viral infection, inflammation, metabolism/endocrine function disorders and neurological disorders. US 2013/0116235 is incorporated herein by reference in its entirety. Alternative names for 2-{3′-hydroxymethyl-1-methyl-5-[5-((S)-2-methyl-4-oxetan-3-yl-piperazin-1-yl)-pyridin-2-ylamino]-6-oxo-1,6-dihydro-[3,4′]bipyridinyl-2′-yl}-7,7-dimethyl-3,4,7,8-tetrahydro-2H,6H-cyclopenta[4,5]pyrrolo[1,2-a]pyrazin-1-one can be used, but the shown chemical structure controls. The US 2013/0116235 publication a useful method for preparing 2-{3′-hydroxymethyl-1-methyl-5-[5-((S)-2-methyl-4-oxetan-3-yl-piperazin-1-yl)-pyridin-2-ylamino]-6-oxo-1,6-dihydro-[3,4]bipyridinyl-2′-yl}-7,7-dimethyl-3,4,7,8-tetrahydro-2H,6H-cyclopenta[4,5]pyrrolo[1,2-a]pyrazin-1-one, but the method requires chromatographic purification and a low yield was achieved.
The US 2013/0116235 publication further discloses a useful five-step process for the preparation of tricyclic lactam compounds used as intermediates in the preparation of 2-{3′-hydroxymethyl-1-methyl-5-[5-((S)-2-methyl-4-oxetan-3-yl-piperazin-1-yl)-pyridin-2-ylamino]-6-oxo-1,6-dihydro-[3,4′]bipyridinyl-2′-yl}-7,7-dimethyl-3,4,7,8-tetrahydro-2H,6H-cyclopenta[4,5]pyrrolo[1,2-a]pyrazin-1-one and having the structure:
In the final step, the above-reference tricyclic lactam compound is generated by ring closure from the following compound:
The multistep process requires two chromatographic purification steps and the overall yield based on the starting material was low.
A need therefore exists for improved method for preparing 2-{3′-hydroxymethyl-1-methyl-5-[5-((S)-2-methyl-4-oxetan-3-yl-piperazin-1-yl)-pyridin-2-ylamino]-6-oxo-1,6-dihydro-[3,4′]bipyridinyl-2′-yl}-7,7-dimethyl-3,4,7,8-tetrahydro-2H,6H-cyclopenta[4,5]pyrrolo[1,2-a]pyrazin-1-one and intermediate compounds therefore.